MADAGASCAR FROGS OF THE GENUS MANTIDACTYLUS. 257 



16. On the Madagascar Frogs of the Genus Mantidactylus 

 Blgr. By G. A. Boulenger, F.R.S., F.Z.S. 



[Received September 18, 1918 : Read October 22, 1918.] 



(Published by permission of the Trustees of the British Museum.) 



Index. 



Page 

 257 



Geographical : 



Madagascar Frogs 



Systematic : 



Mantidactylus, Synopsis of Species .! 



M. ambohimitombi, sp. n 



Aqlyptodactylus, g. n., for Limnodytes madagasca riensis 



258 

 260 



A. Dum 



261 



Among the many peculiar features of the herpetological fauna 

 of Madagascar is the fact of the genus Rana, so numerous in 

 species in Continental Africa and the Indo-Malayan Region, 

 having only two representatives : R. (Tornopterna) labrosa Cope, 

 allied to the South African R. natalensis A. Smith, and R. (Pty- 

 chadena) mascareniensis D. & B., distributed over the greater 

 part of Africa, the Seychelles and the Mascarenes included. 



Most of the Madagascar frogs originally referred to liana or 

 Limnodytes (Hylorana) have proved to be distinguished by the 

 presence of an intercalated bone between the penultimate and 

 distal phalanges of the fingers and toes and have been referred to 

 an autochtonous genus, Mantidactylus *. In the species grouped 

 by me under this genus, the swellings or discs in which the 

 fingers and toes terminate bear on the lower surface a ring-shaped 

 groove, defining a circular or transversely elliptic area, thus afford- 

 ing a further distinctive character by which to recognise them 

 among those species of Rana in Which digital discs are likewise 

 present. 



One species, Limnodytes madagascariensis A. Dum. (R. ingui- 

 nalis Gthr.), which I had left in the genus Rana, has been shown 

 by the late Dr. F. Mocquard to be also provided with the inter- 

 calary phalanx and therefore referred by him to Mantidactylus ; 

 but as in this species the small digital terminal expansions are 

 devoid of the groove to which I now draw attention, I consider 

 it to be entitled to generic distinction, under the new name of 

 Aglyptodactylus. In this A. madagascariensis, the omosternum 

 is forked at the base, as in Mantidactylus, the nasal bones are 

 small, oblique, and separated from each other as well as from the 

 frontoparietals, and the terminal phalanges are obtuse ; there are 

 no femoral glands. 



We are now acquainted with 22 species of Mantidactylus, to 

 which a twenty-third is here added. A key to the identification 



* Ann. & Mag. N. H. (6) xv. 1895, p. 450. 



